﻿* Encoding: UTF-8.
* Hierarchical regression analyses GROUP #3 = Bayley 24 months & WPPSI 6 years

*Select variables without missings for centering Bayley & WPPSI variables.
COUNT
  nomisBayleyWPPSI = Group M3_Bayley_NL_Cognition_Index_corrected M3_Bayley_NL_Motor_Index_corrected M3_Bayley_NL_Language_Index_corrected
  M5_WPPSI_FSIQ_corrected (MISSING).
FREQUENCIES
  VARIABLES=nomisBayleyWPPSI
  /ORDER=  ANALYSIS.
EXECUTE.

USE ALL.
COMPUTE filter_$=(nomisBayleyWPPSI eq 0).
VARIABLE LABEL filter_$ 'nomisBayleyWPPSI eq 0 (FILTER)'.
VALUE LABELS filter_$  0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE .

DESCRIPTIVES
  VARIABLES=Group M3_Bayley_NL_Cognition_Index_corrected M3_Bayley_NL_Motor_Index_corrected M3_Bayley_NL_Language_Index_corrected
  M5_WPPSI_FSIQ_corrected
  /STATISTICS=MEAN STDDEV MIN MAX .
EXECUTE.

*Center variables.
COMPUTE c3M3_Bayley_NL_Cognition_Index_corrected = M3_Bayley_NL_Cognition_Index_corrected - 102.28.
EXECUTE .
COMPUTE c3M3_Bayley_NL_Motor_Index_corrected = M3_Bayley_NL_Motor_Index_corrected - 103.99.
EXECUTE .
COMPUTE c3M3_Bayley_NL_Language_Index_corrected = M3_Bayley_NL_Language_Index_corrected - 107.41.
EXECUTE .

*Compute interaction variables.
COMPUTE i3GroupM3Cognition = c3M3_Bayley_NL_Cognition_Index_corrected * Group.
EXECUTE .
COMPUTE i3GroupM3Motor = c3M3_Bayley_NL_Motor_Index_corrected * Group .
EXECUTE .
COMPUTE i3GroupM3Language = c3M3_Bayley_NL_Language_Index_corrected * Group.
EXECUTE .

*Regression analysis Bayley & FSIQ
Step 1 (enter maternal education & group)
Step 2 (enter centered variables) 
Step 3 (enter interaction variables).
REGRESSION
  /descriptives cor
  /MISSING LISTWISE
  /STATISTICS COEFF CI(95)OUTS R ANOVA BCOV CHANGE collin tol
  /CRITERIA=PIN(.05) POUT(.10)
  /NOORIGIN
  /DEPENDENT M5_WPPSI_FSIQ_corrected
/METHOD=ENTER Maternal_education Group
 /METHOD=ENTER c3M3_Bayley_NL_Cognition_Index_corrected c3M3_Bayley_NL_Motor_Index_corrected c3M3_Bayley_NL_Language_Index_corrected
/METHOD=ENTER i3GroupM3Cognition i3GroupM3Motor i3GroupM3Language.

*Regression analysis Bayley & VIQ
Step 1 (enter maternal education & group)
Step 2 (enter centered variables) 
Step 3 (enter interaction variables).
REGRESSION
  /descriptives cor
  /MISSING LISTWISE
  /STATISTICS COEFF CI(95)OUTS R ANOVA BCOV CHANGE collin tol
  /CRITERIA=PIN(.05) POUT(.10)
  /NOORIGIN
  /DEPENDENT M5_WPPSI_VIQ_corrected
/METHOD=ENTER Maternal_education Group
 /METHOD=ENTER c3M3_Bayley_NL_Cognition_Index_corrected c3M3_Bayley_NL_Motor_Index_corrected c3M3_Bayley_NL_Language_Index_corrected
/METHOD=ENTER i3GroupM3Cognition i3GroupM3Motor i3GroupM3Language.

*Regression analysis Bayley & PIQ
Step 1 (enter maternal education & group)
Step 2 (enter centered variables) 
Step 3 (enter interaction variables).
REGRESSION
  /descriptives cor
  /MISSING LISTWISE
  /STATISTICS COEFF CI(95)OUTS R ANOVA BCOV CHANGE collin tol
  /CRITERIA=PIN(.05) POUT(.10)
  /NOORIGIN
  /DEPENDENT M5_WPPSI_PIQ_corrected‎
/METHOD=ENTER Maternal_education Group
 /METHOD=ENTER c3M3_Bayley_NL_Cognition_Index_corrected c3M3_Bayley_NL_Motor_Index_corrected c3M3_Bayley_NL_Language_Index_corrected
/METHOD=ENTER i3GroupM3Cognition i3GroupM3Motor i3GroupM3Language.

*Regression analysis Bayley & PSQ
Step 1 (enter maternal education & group)
Step 2 (enter centered variables) 
Step 3 (enter interaction variables).
REGRESSION
  /descriptives cor
  /MISSING LISTWISE
  /STATISTICS COEFF CI(95)OUTS R ANOVA BCOV CHANGE collin tol
  /CRITERIA=PIN(.05) POUT(.10)
  /NOORIGIN
  /DEPENDENT M5_WPPSI_PSQ_corrected
/METHOD=ENTER Maternal_education Group
 /METHOD=ENTER c3M3_Bayley_NL_Cognition_Index_corrected c3M3_Bayley_NL_Motor_Index_corrected c3M3_Bayley_NL_Language_Index_corrected
/METHOD=ENTER i3GroupM3Cognition i3GroupM3Motor i3GroupM3Language.
